In 1942, Winston Churchill arrives in Algiers with plans to push on to Casablanca for the Casablanca Conference, where he would meet Franklin D. Roosevelt and Joseph Stalin. Despite the strong warnings of his aides and army commanders against rail travel, Churchill remains resolute, determined to move by train rather than by air.
Intelligence quickly reveals that the Germans are aware of his presence, and they fear a kidnapping or assassination attempt. To protect him, an especially secure carriage is attached to a train known as the Casablanca Express, and a small team of American commandos is assigned to accompany him. Three intelligence agents—Alan Cooper, Captain Franchetti, and Lt. Lorna Fisher—are tasked with guarding the mission, though Cooper is briefly pulled back after pursuing a French double agent.
Unbeknownst to the defenders, a German operative, Otto von Tiblis, is traveling undercover among the passengers. Franchetti spots the deception, and a tense fight erupts on the coach roof. Von Tiblis is finally exposed, pulls a weapon, and seizes control of the locomotive, halting the train. At that moment, a contingent of German paratroopers erupts from nearby, engaging the riders and wreaking havoc as they kill and wound American soldiers and passengers alike.
Back in Algiers, Allied intelligence pieces together the attempted kidnapping and dispatches Cooper on a dangerous solo mission. He travels across the desert by camel and stealthily approaches the train. The coaches are wired with explosives, but Cooper manages to drag a badly wounded Franchetti under the cars and cut the wires linking the charges to their detonators. With time running out, Cooper, Fisher, and Franchetti open fire on the German invaders as Fisher manages to transmit an emergency radio signal to Algiers, prompting a trainload of heavily armed U.S. Marines to depart and intercept the Express.
The German assault is halted and all the attackers are killed, yet von Tiblis somehow reanimates the engine and faces the Marines in a blazing confrontation on the moving train. He is finally killed when the Marines overwhelm him, ending the immediate threat to the passengers. Franchetti dies in the melee, while Cooper and Fisher, though gravely wounded, make it back to Algiers.
In the aftermath, the surviving operatives discover the shocking truth: the Churchill they protected on the train was a decoy. The real Churchill had already reached Casablanca by plane, changing the course of the mission and the broader war effort. The mission, despite its costs, is remembered as a tense, high-stakes stand in the broader effort to secure a pivotal Allied conference.
